There is a general need to know whether perishable products and materials have or have not expired prior to consumption or use. For example, it is important to know in restaurants that uncooked meats and poultry have been properly stored at low temperatures and have not exceeded the time frame necessary to maintain freshness. Proportioned foods are periodically turned over and it is critical to monitor the timing and turnover rate accurately to ensure patron safety. In food service organizations, large quantities of perishable foods must be inventoried in preparation for designated preparations. Often large pans, containers, and vats must be periodically used and cycled. It is therefore essential to monitor directly the time and temperature history of perishable food items to ensure maximum freshness and minimum potential pathogenic colonization.
There is concern by food and beverage producers that the products they produce are properly handled throughout the distribution cycle and that safe time and storage temperatures are maintained. It is desirable that at the specific time a perishable item is produced that the time and temperature profile of the food item be monitored cost effectively and directly without the need of employing complicated monitoring equipment or devices which require special handling and storage.
Although dating and color labeling can be used as a means to distinguish and inventory a particular perishable item, complications arise in keeping track of dates, knowing the correct date used, correlating a future date with the present date and remembering the meaning of a particular color which is intended to indicate a particular date of use. It is generally complicated and often inaccurate when relying on an indirect inventorying method to determine when a particular perishable item should or should not be used.
Inventorying methods do not integrate the time and temperature history of a particular item.
Desirably, a device capable of accurately indicating the time and temperature history of a perishable product would find practical use if the device could be initiated for monitoring precisely at the time when the perishable product is to be stored in preparation for serving in a coming period. The initiation process should be able to be initiated at the time intended and not well in advance of use. Advance preparation and initiation of such a device may defeat the utility since a means to store such a device may lead to questions about the very questions that the device is intended to monitor.
It is of particular interest to provide a continuum of answers as to the storage and treatment of perishable products. Perishable items typically undergo exposure to various temperature and other storage conditions as well as changes in temperature during preparation, cooking, cooling, and subsequent storage. It is often desirable to monitor and determine the condition of a particular perishable item for food safety, palatability, thoroughness of cooking, and integrity during subsequent storage. Indicators capable of following and reporting the conditions of perishables during the continuum of conditions provide a variety of advantages over devices, thermometers, discrete monitoring or the like which are only capable of reporting one parameter of a condition which a perishable item is exposed to.
Ideally, a simple indicating device capable of a plurality of monitoring capabilities should be simple to use, accurate to interpret, and provide only a minimal incremental expense to the overall cost of the perishable item to be monitored.
Plural intrinsic expiration initiation application indicators are provided comprising an initiation means in which a soluble unreacted composition is applied to a substrate surface and is capable of monitoring/indicating multiple sequential or simultaneous processes. Initiation of the indication process is achieved by evaporation of a solvent and formation of a solid phase of the unreacted composition. When the composition forms a solid, it is intrinsically reactive to its thermal environment resulting in polymerization and subsequent color formation that can measure environmental parameters. The degree of color formation and the intrinsic color hue is a function of the temperature environment to which the substrate and indicating means are subjected. The degree of color formation and color hue can be calibrated to both a schedule for expiration and to have the plural ability to indicate environmental exposed temperatures. Subsequent environmental conditions can be monitored wherein the device can further change color in response to a plurality of differential environmental conditions an item is exposed to. Various substrates, formats and devices for delivering the soluble unreacted composition may be employed for a variety of situations requiring monitoring of expiration of an item of interest.